Lack of CD44 variant 6 expression in rectal cancer invasive front associates with early recurrence

AIM: To investigate the prognostic value of CD44 variant 6 (CD44v6), a membranous adhesion molecule, in rectal cancer.METHODS: Altogether, 210 rectal cancer samples from 214 patients treated with short-course radiotherapy (RT, n = 90), long-course (chemo) RT (n = 53) or surgery alone (n = 71) were studied with immunohistochemistry for CD44v6. The extent and intensity of membranous and cytoplasmic CD44v6 staining, and the intratumoral membranous staining pattern, were analyzed.RESULTS: Membranous CD44v6 expression was seen in 84% and cytoplasmic expression in 81% of the cases. In 59% of the tumors with membranous CD44v6 expression, the staining pattern in the invasive front was determined as “front-positive” and in 41% as “front-negative”. The latter pattern was associated with narrower circumferential margin (P = 0.01), infiltrative growth pattern (P < 0.001), and shorter disease-free survival in univariate survival analysis (P = 0.022) when compared to the “front-positive” tumors.CONCLUSION: The lack of membranous CD44v6 in the rectal cancer invasive front could be used as a method to identify patients at increased risk for recurrent disease.     

DNA Flow Cytometry in Surgically Treated Lung Cancer: Prognostic Significance

Although DNA aneuploidy and high proliferative activity (S-phase fraction, SPF) of tumour cells, measured by flow cytometry, have proved to be indicators of poor prognosis in most solid tumours, there have been conflicting results in lung cancer studies. During a four-year period we studied the prognostic significance of DNA ploidy and SPF in 99 surgically treated lung cancer patients. Flow cytometric analysis was done from archival, formalin-fixed, paraffin-embedded tumour specimens. DNA index and SPF were determined, using MultiCycle software with sliced nuclear correction to compensate for debris. There were 61 DNA diploid and 38 DNA aneuploid tumours. The median SPF was 10.2%. Neither ploidy nor SPF was associated with previously known prognostic factors. Survival was poorer in patients with aneuploid tumours than in the other patients, but the difference was not statistically significant. DNA ploidy and SPF thus do not seem to be useful prognostic indicators in surgically treated lung cancer.     

Ruling Out Myocardial Infarction with Troponin T and Creatine Kinase MB Mass: Diagnostic and Prognostic Aspects

Objective - To investigate the time window for ruling out myocardial infarction (MI) with troponin T (TnT) and creatine kinase isoenzyme MB mass (CK-MBm) and the prognosis of patients with ruled-out MI diagnosis. Design - The study was based on 397 patients admitted with a suspected acute coronary syndrome but with relief of symptoms within 24 h. Results - MI diagnosis was confirmed with elevated TnT (> 0.10 µg/l) in 108 patients, in 91% within 12-24 h from the onset of symptoms, and in 99% within 12 h from admission. In 94 of these patients CK-MBm became elevated (> 5.0 µg/l), in 95% within 10-12 h from the onset of symptoms, and in 99% within 6 h from admission. Among patients with ruled-out MI diagnosis, the 1-year incidence of recurrent coronary events was 29% in those with positive history of coronary heart disease (CHD) but only 7% in those without prior CHD ( p < 0.001). Conclusion - Using TnT or CK-MBm, MI can be ruled out within 12 h from admission in the majority of patients. Among patients with ruled-out MI diagnosis, positive history of CHD is an important determinant of prognosis.     

Automated GMP production and long-term experience in radiosynthesis of CB1 tracer [18F]FMPEP-d2

Here, we describe the development of an in-house-built device for the fully automated multistep synthesis of the cannabinoid CB₁ receptor imaging tracer (3R,5R)-5-(3-([¹⁸F]fluoromethoxy-d₂)phenyl)-3-(((R)-1-phenylethyl)amino)-1-(4-(trifluoromethyl)phenyl)pyrrolidin-2-one ([¹⁸F]FMPEP-d₂), following good manufacturing practices. The device is interfaced to a HPLC and a sterile filtration unit in a clean room hot cell. The synthesis involves the nucleophilic ¹⁸F-fluorination of an alkylating agent and its GC purification, the subsequent ¹⁸F-fluoroalkylation of a precursor molecule, the semipreparative HPLC purification of the ¹⁸F-fluoroalkylated product, and its formulation for injection. We have optimized the duration and temperature of the ¹⁸F-fluoroalkylation reaction and addressed the radiochemical stability of the formulated product. During the past 5 years (2013–2018), we have performed a total of 149 syntheses for clinical use with a 90% success rate. The activity yield of the formulated product has been 1.0 ± 0.4 GBq starting from 11 ± 2 GBq and the molar activity 600 ± 300 GBq/μmol at the end of synthesis.     

Automated production of [18F]FTHA according to GMP

14‐(R,S)‐[¹⁸F]fluoro‐6‐thia‐heptadecanoic acid is a tracer for fatty acid imaging by positron emission tomography. High demand for this tracer required us to replace semiautomatic synthesis with a fully automated procedure. An automated synthesis device was constructed in‐house for multistep nucleophilic ¹⁸F‐fluorination and a control system was developed. The synthesis device was combined with a sterile filtration unit and both were qualified. 14‐(R,S)‐[¹⁸F]fluoro‐6‐thia‐heptadecanoic acid was produced according to good manufacturing practice guidelines set by the European Union. The synthesis includes an initial nucleophilic labelling reaction, deprotection, preparative HPLC separation, purification of the final product, and formulation for injection. The duration and temperature of the reaction and hydrolysis were optimized, and the radiochemical stability of the formulated product was determined. The rotary evaporator used to evaporate the solvent after HPLC purification was replaced with solid phase extraction purification. We also replaced the human serum albumin used in the earlier procedure with a phosphate buffer‐ascorbic acid mixture in the final formulation solution. From 2011 to 2016, we performed 219 synthesis procedures, 94% of which were successful. The radiochemical yield of 14‐(R,S)‐[¹⁸F]fluoro‐6‐thia‐heptadecanoic acid, decay‐corrected to the end of bombardment, was 13% ± 6.3%. The total amount of formulated end product was 1.7 ± 0.8 GBq at end of synthesis.     

Brown adipose tissue function is accompanied by cerebral activation in lean but not in obese humans

Brown adipose tissue (BAT) is able to generate heat and dissipate energy in response to cold exposure in mammals. It has recently been acknowledged that adult humans also have functional BAT, whose metabolic activity is reduced in obesity. In healthy humans, the cerebral mechanisms that putatively control BAT function are unclear. By using positron emission tomography (PET), we showed that cold-induced BAT activation is associated with glucose metabolism in the cerebellum, thalamus, and cingulate, temporoparietal, lateral frontal, and occipital cortices in lean participants, whereas no such associations were found under warm control conditions. The cold-induced increase in cerebral glucose metabolism was more robust in lean than obese participants. Cerebral glucose metabolism was not associated with skeletal muscle or white adipose tissue glucose uptake under warm or cold conditions. In conclusion, BAT metabolism was accompanied by the activation of specific cerebral regions, and this shows an uncharacterized role that the brain plays in the regulation of BAT function. In obese participants, the cold-induced response in cerebral activity was attenuated that provides a clue for obesity-induced impairment in BAT metabolism.